"Surely you accept, PG, that any collector of traditional songs (rather than anonymous poetry) of note (if you'll pardon the pun) would have had a recording device &/or the ability to notate."

I'm quite sure, on the contrary, that many notable collectors did not have recording devices ~ those who worked prior to the invention of (or, at least, the widesprad availability of) recording technology.

And whether or not they had the ability to write musical notation, many transcribers/collectors/publishers of broadsides, etc., gave us WORDS ONLY for pieces they themselves describe as "songs," clearly implying that music existed, even though it may not have been notated.

Look, if you LIKE single-note melodies to the exclusion of any kind of harmony and accompaniment, that's your prerogative and no one begrudges you youe enjoyment.

But I think I speak not only for myself but also for quite a few others that your insistence that harmony singing ~ a very basic aspect of homespun music-making and the enjoyment thereof ~ can't possibly have existed in the past SIMPLY BECAUSE THERE IS NO WRITTEN DOCUMENTATION OF IT is just too exasperating for us to let it pass.